Prefocused incandescent electric lamp



May 27, 1930. D. s. GUSTIN PREFOCUSED INCANDESG'ENT ELECTRIC LAMP Filed voct. 5, 1925 INVENTOR DANIEL s. GUSTiN ATTORNEY Patented May 27, 1930 UNITED STATES PATENT OFFICE DANIEL SNYDER GUSTIN, OF EAST ORANGE, NEW JERSEY, ASSIGNOR T0 -WESTINGI- HOUSE LAMP COMPANY, A. CORPORATIN- 0F PENNSYLVANIA AIImr'ocusisn rNcANDEscENT ELECTRIC LAMP l application mea october 5, 1925.l serial No. 60,383..

trical devices, such for example as an incandescent electric lamp, when using such lamps in connection with apparatus wherein the light source must be positioned on a focal line,

`it is essential that the light source be posi-I tively and accurately positioned' with respect to the means for securing the base to the apparatus.

Heretofore accuracy-in the disposition of a filament .for optical purposes has been obtained' by the provision of expensive adjustable lamp supporting structure. On the other hand, lamps have been manufactured with a standard base-and provided withl auxiliary means for attaining a predetermined dimension between the light ,source and the base. so that when a lamp was positioned in a socket the light source would be located in a prede- -termined position.

The necessity lfor the various expedients resorted to in properly locating a filament resulted from the fact that in the manufacture of an incandescent lamp under the' usual' standard practice, certain manufacturing inaccuracies occur which result` in a slight variation in the position of a filament from the required focal position. It is, of course, possible that some filaments duringA the manufacturingof a lamp may be located properlybut in orderto insure a uniform product .1n

the form of a lamp which may be employed for optical purposes', it is necessary that each lamp be so constructed that the filament will be positively positioned in a predetermined relation Ato the base portionof the bulb and within a very narrow tolerance.

fore', to provide a method of manufacturing an elect'rlcal device such as an incandescent lamp 1n such manneras to'meet manufactur- Another object .of the invention is to provide aflamp bulb with a base applied to a bulb in the usual manner and adapted for a subsequent operation'so that when applied to` a socket the light source will be located in a` predetermined position to said socket. Another object of the invention is to prowith the usual commercial accuracy and subsequently pierced to receive` engageable members to hold the bulb with the filament there!` of in a lpredetermined positionzv Another object of the invention is to pro- -vide a lamp having a base adapted to be videa lamp w1th a co-operativesocket to re- '5 pierced to provide apertures in a given relation to a filament;

y Another object of the invention is to `pro'- l vide a method of adjusting .a' lamp filament with respect to a supporting member by operations u on the base of the lamp to adapt Y thesame or co-operations with ajsocket.

.- Other vobjects and advantages A will be `understood by reference to the following description.

In practicing the present invention I may provide` an ordinary 'electric incandescent lamp with a blank or plain cylindrical form of I base.` The lampv may be constructed in the usual manner according to the common' factory practice with only the usual commercial accuracy in locating the base in a given relative position with respect to a filamentwithin a bulb'. A lamp so produced may, according -to my invention, be'appliedto a suitable-fixture for supporting the lamp in relation to a lens system.v The filament of the lamp may then be heated to produce a light source and the image reflected upon a .suitable screen having divisions to indicate whether or not.

, the filament is properly p'ositioned. The An object o f the present invention is, there-4 lamp may then b'eadjusted until the reflected image showsthat the filament is in a predetermined position. Means are provided for l .producing apertures in the base of the bulb .ing conditions and to produce devices .in

which the light source is uniformly disposed.-

to receive engagea-ble members of a socket. The lamp may be moved vertically or laterally until the image of the filament is properly located and punctures or apertures may `ment with the edges ofthe notches and the invention further contemplates the provision of a socket having suitablemovable engaging membersv corresponding i'n number to the apertures in said base. When, therefore, a lamp base is inserted into the provided socket the movable members engagey with the notches and hold the bulb with the light source a predetermined distance above the socket and consequently properly located with respect to the focal line of the system in which the lamp is employed.

It will be understood that sockets, as provided in accordance with the present invention, are to be properly positioned with respect to the refiector or element such as lens or mirror and that when a system is properly constructed lamps manufactured in accordance with the foregoing will be applicable for accurate disposition in such system. It`will be evident that by reason of the present method and structure employed that a lamp may be manufactured inl a rapid and economical manner under factory conditions, and that such lamps will be universal in uniformity so that when appliedto a socket no discrepancy will occur with respect to the location of the light source relative tothe focal line of the system or apparatus to which the lamp is applied.

The invention will be more fully understood by reference to the accompanying drawing in which:

Fig. 1-is a side view of a lamp and socket constructed in accordance with the present invention and rshown partly in section.

Fig. 2 is a fragmentary perspective view of a base having notches with edges toengage with movable members of a socket.

Fig. 3 4is a vertical sectional view of a socket having movable members to engage with the edges of notches of a base. f

Fig. 4 shows a fixture for cutting slots at predetermined points in a base.

Fig. 5 shows another fixture whereby portions of the Wall of a base may be bent inwardly adjacent to predetermined positioned slots.

Fig. 6 shows, diagrammatically, a lens system for projecting an image of a light source upon a screen. v

Fig. 7 is'a front view of a screen showing cross lines for locating an image.

-' 'Fi l8 isa diagrammatlc representation of an a igned filament and shows an exaggerated relation of a filament with respect to the meansfor locking the base in a socket.

Fig'. 9 is a fragmentary view of a base and jshows a modified form of notch.

A bulb F Fig. 10 is a fragmentary view of a socket showing' one of the movable members for engaging with the edge of the notch shown in Fig. 11 shows a section of a base having notches pressed therein without perforating the shell and Fig. 12 shows a spring member of a base bent to provide'a relatively large and contacting surface.

vThe invention may be practiced in connection with any electrical device employing a base'or plugfor application to a socket. The embodiment of the invention herein illustrat ed comprises a base 10 secured to a bulb 11 in the usual manner. The bulb may contain a light source or filament 12 mounted on su port members 13 embedded in a press 14 o a stem 15 which is sealed to the bulb y11 in the usual manner. The light source 12 may be of any type or form dependinoupon the character of the bulb employed. rdinarily, the distance between the base and the center of the filament varies slightly due to the failure of an operator to exercise the necessary care ini properly positioning the filament when the`y lamp is made, that is, in properly disposing and securin the base to the'bulb.

Ordinari y in the manufacture of incandescent electrical lamps insuiicient accuracy is attained in positioning the filament for ordinary purposes. However, in the manufacture of lamps for use in connection with optical systems it is necessary that the light source of a lamp havea definite position with respect to the support thereof when disposed for operation. The usual commercial accuracy is not sufficient to produce a lamp with the light center of all lamps uniformly positioned. For the purpose of constructing a lamp to co-operate with a socket and to hold a filament in a predetermined position the base 10 may be blank when applied as by cementing to the bulb A11. As illustrated in Fig. 1 a socket 16 is provided to receive the base of the lamp, and may be provided with resilient, movable membersl'?, ends of which `ma project from a Wall or shell 18 of the soc et 16. The movable members ma be provided in any suitable manner an as shown, mayconsist of inwardly bent projecting tongues or spring members suitably secured to the shell 18. The shell may be fastened in a non-conductive casing 19 and held in place b a bolt 21 which bolt ma be provided wit a contact member 22. lDisposed in a centrally located aperture 23 of the casing 19 is positioned a stem 24 having anvenlarged end 25.to serve as a contact for en-` gagement with lower central contact member izo 26 of the base 10. `The stem 24 may be ten- 28 of the stem 24 may project from the casing 19 and may be providedvith a contact 29.v

The socket 16 may be positioned in a lamp housing or other device which employs an 'electric incandescent bulb: the socket being cured in a socket and with the lament dis' posed in a predetermined position; For-a0.- complishing the above a blank base of a lamp is provided with notches or depressions 31 (see Fig. 2) into which the tongues or members 1-7 move when a base is introduced into the socket 16. The notches 31 are so formed as to provide relatively straight edges 32 for engagement with ends 33 of the members 17.

A basemay be secured to a bulb with only the usual accuracy and provided with edges .-32 located a predetermined distance from the center of the light source. The lamp thus constructed when disposedin a socket so that the edges 32 are held against the ends 33 of the member 17, will be properly disposed with the filament in a predetermined position.- If,.in addition to being out of p0si' tion along the axial line of the bulb, the mount supporting the filament is slightly out of alignment so as to cause a lateral dis.

placement of the filament, the notches 31 may be so disposed as to compensate for such variation and bring the filament coincident vvith a given point on a predetermined focal ine. Y

The present plates the formation of the notches-31 in -a base at' predetermined distances from the light source so that whenthe base is inserted for co-operation with a `socket the proper disposition of the filament will be attained. A lamp manufactured in accordance with the present invention may be produced With the usual commercial accuracies in so far as the assembly and union of the component parts of the lamp are concerned, the lamp or bulb having a base capable of being operated upon to be provided with notches or edges for the engagement with movable members of a socket.

Any suitable means may be employed for piercingor punching the base to produce the notches and as shown in Fig. 6 a jig or fixture 34 may be provided in the forni of a bracket having a centrally located opening 35, having rounded edges to permit a lateral adjustment of a bulb. n

-A spring actuated member 36' may be provided to enga e the lowercontact 26 of thebase when the ulb is positioned in the fixture or bracket 34. The bracket may be metal-and servef as a conductor by reason of its contact with the base 10 while the member 36 -may serve as the opposite contact. Leads 37 'skilled in the art.

invention, therefore, contemelectrical current from any suitable source i of electrical energy (not shoWn),-thus the filament of a lamp lmay be heated to incan descence to provide Va light source. bracket or fixture 34 maybe part of aprojection stem including a screen 39 and a lens 41.4 The lens may serve to project an image -40 of the filament upon't'he screen 39 and The v a'vertical axial line a mirror 44 is provided in co-operation with a lens 45 to throw an image-of the upper portion of the' filament upon the screen 39 .so that by adjusting the lamp to locate. the filament with respect to .hair lines 46 and 47, a lateraladjustment 'of the filament with respect to a given point is attailned. When so adjusted suitable rotating cutters 48 may be moved to vform slots in the wall of the-base and thus produce the edges 32. Any suitable means may be employed for reciprocating the rotating cutters, the drawing merely showing the same in a more or less diagrammatic manner in o rder to convey a method of cutting the wall of the base-which will be obvious 'to those Inasrnuch as the cutters operate in a common fixed plane, it will be appreciated that no matter where the fila ment may be located with respect to the base,

by reason of the commercial inaccuracies,

...the slots may be cut a predetermined dis- .tance from the center of the filament in every bulb ap lied to the fixture or system.

It wil be understoodthat in lamps produced under ordinary factory conditions the variation in the position of a filament with respect to a focal line governed by the relation ofthe base to the filament, or the position of the filament with respect to the axial line' of the bulb do-es notvary to any considerable degree, that is the variation may be from a 32d to 1%, ofl an inch. This variation is too great for proper alignment of the filament on a predetermined line when the bulb is positioned in asocket but is within a range the said annulus will engage the upper edge y of the groove or incision formed and depress the wall to pro-vide a cavity or curved surface 5,1 (see Fig. 2.) to give clearance for the members 17 and permit their engagement with the edges 32. These curved portions, or depres-` sions 51, also serve as'guides for removing the members 17 from engagementwith the edges 32.

When a lamp base has been inserted into a socket and the members 17 have snapped into engagement with the edges 32 it will be apparent that the lamp will be locked against a direct vertical pull. After the lamp and base thereof is rotated, however, the members 17 will traverse the curved surfaces 51 and ride toward the cylindrical portion of the base, thus permitting a removal of the same end 53 shown in Fig. 10. When employing a lamp such angular' or pointed members 17 in the socket', bases 10 may be provided with cooperating inverted V- shaped edges 54 (see Fig. 9). With this construction the lamp,

when in the socket, is more rigidly held and centered against rotary movement.

As illustrated in Fig. 11 notches or recesses 55 may be formed in the base 10. The recesses may be so shaped as to provide an edge' or strai ht surface 56 for engagement with the mem ers 17 of a socket. The members 17 as shown in Fig. 12 may be made with their ends bent to provide contact surfaces 57 to af-v ford a broader surface for engagement with the edges 32 of the notches 31 of the base 10. From the foregoing it will be evident that manufactured .with the filament slightly off-center may be provided with slots locatediby the above described optical means, which slots may lie in a plane indicated by the line 58 shown "1n Fig. 8.

A filament which was positioned slightly olf-center in a lamp may be positioned by the above described adjusting means, at the in tersection of a predetermined axialline 59 and the focal line 61. The distance between tlie plane 58 and the filament 12, and consequently the distance between the edges 32 of the base and the'filament, will always be a predetermined distance, thus bringing the iila-l ment 'in the proper focal line as may be determined by the position of the socket in a lamp structure as used for signal', automobile, search lights or other service. The socket 16 may be sufficiently larger in-diameter than the baseof a lamp to allow for sidewise adjustment for engagement with the 'spring members 17. A bead 62 may be provided when desired at the upper edge of the socket to .hold the base centralwith respect'to the socket and allow for a slight sidewise adjustment. l o

In optical systems or lamp housmgs employing the present socket, it is to be understood that the socket is so positioned that when a bulb is inserted therein a filament will occupy thedesired position with res ect to the optical or projection system and o vioulsly one lamp may be substituted for another l ing a bulb, a filamentin said bulb, a base secured to said bulb, slots formed in said base in predetermined positions with respect to said filament and a concave portion formed fromsaid base'adjacent each of said slots.

2. The method of manufacturing an in candescent electric lamp which comprises providing a bulb having a filament therein and a base secured to the bulb 4in the usual manner, adjusting the lam by optical means to determine a plurality o points on the base at predetermined distances from said {ilament and lin perforating the base at said points.

3. The method of manufacturing an incandescent electric lamp which comprises providing a bulb having a filament therein and a base secured to the bulb in the usual manner, adjusting the lamp by vertical or lateral movement and determining by optical means when the filament is in a given position and in forming engageable members from the base disposed in predetermined positions with respect to the distancefbetween the filament and said members and to the axial alignment of said filament.

4. The method of manufacturing an incandescent electric lamp which comprises providing a bulb having a filament therein anda base secured to the bulb in the usual manner adjusting the lamp by vertical or lateral movement or both and determining by optical means when the filament is in a predetermined position and in piercing the'wall of said base to provide engageable edges in given positionsl with respect to the distance between the lament and said edges and toIk the axial alignment of said filament.

5. The method of so `constructing a lamp having a luminous body in a bulb that said luminous body assumes a predetermined podetermined angular relation to and at a predetermined distance from said luminous body and located to cooperate with said pins of said socket. I

6. The method of basing a lamp or similar device comprising a sealed glass bulb containing a luminous body, which consists inl securing to said bulb with only usual com# mercial accuracy a tubular metallic base shell and then making in the wall of said shell engaging fasteners at predetermined points in fixed and predetermined relation to said luminousbody in the bulb.

7 'The method o f basing a lamp or similar device comprising a sealed glass bulb containing a luminous body which consists n cementing oneend of a metallic tubular base shell to said bulb in the usual Way, and then -forming pin engaging holes inthe Wall of said shell and at a xed and predetermined distance from and in predetermined angular relation to said luminous body in the bulb.

' In testimony whereof, I have hereunto subscribed my name this 3rd day of October,

DANIEL SN YDER GUSTIN. 

